On 2016-07-18 09:07:19 +0530, Amit Kapila wrote: > + /* > + * Before locking the buffer, pin the visibility map page if it may be > + * necessary. > + */ > > + if (PageIsAllVisible(BufferGetPage(*buffer))) > + visibilitymap_pin(relation, block, &vmbuffer); > + > LockBuffer(*buffer, BUFFER_LOCK_EXCLUSIVE); > > I think we need to check for PageIsAllVisible and try to pin the > visibility map after taking the lock on buffer. I think it is quite > possible that in the time this routine tries to acquire lock on > buffer, the page becomes all visible.
I don't see how. Without a cleanup lock it's not possible to mark a page all-visible/frozen. We might miss the bit becoming unset concurrently, but that's ok. Andres -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
